Without resorting to editing the host file (as shown in this Apple.SE thread), is there any way to add a new search engine option to Safari for Windows? Glims works great on OS X, but unfortunately is not an option since my work machine is a Windows 7 box.

EDIT: I'd prefer a generic solution, similar to Glims, that would allow me to add any search engine to the search options.

This is not possible. Safari currently does not let you use anything outside of Google, Bing, or Yahoo, without doing hacks like those you linked to.

The only other option would be to use a Safari Extension if the search provider you want to use offers one.

Many of the Safari plugins on the Mac use very Mac-specific API's and are more of additions to Safari through the Mac OS versus plugins that would be less platform-specific. Therefore, many plugins like this would have to be completely redone on Windows.